1 On July 20, 1969, millions of people gathered around their TV sets. They watched an amazing event! It was the day a man walked on the moon for the very first time! That man was American astronaut Neil Armstrong. As he stepped onto the rocky surface of the moon, Mr. Armstrong spoke the famous words, "That's one small step for man, one giant leap for mankind."2 Space travel began 12 years before that. On October 4, 1957, Russia sent Sputnik I into space. Sputnik I was a satellite. That is an object that orbits or travels around the sun, Earth, or other heavenly body. Sputnik I was an artificial satellite. That means it was man-made. (The moon is a natural satellite.) Today, man-made satellites have many uses. Some collect information about the weather and send it back to Earth. Others send radio, television, and telephone signals from one place on Earth to another. Artificial satellites can also help sailors or airplane pilots find their way during a bad storm. Some can even spy on the enemy during a war!3 Russia put Sputnik II into space in November 1957. It carried a dog named Laika. Laika was the first animal sent into space. Scientists studied how animals lived in space. That helped them learn how to send humans there, too.